Research On The Bending Characteristics Of Flexible Arm And Its Application In Pipeline Robots

Flexible manipulators have significant advantages such as multiple degrees of freedom,multi-direction bending and flexible layout,and are widely used in industry.In response to the needs of drainage pipeline inspection robots and dredging robots,this paper developed a mechanical spring-type flexible arm driven by a motor-wire rope and a composite hose-type flexible arm driven by a swing cylinder.The bending characteristics of the two mechanical flexible arms were analyzed by applying the theory of mechanics.Passed the experimental verification and successfully applied to the drainage pipeline inspection and dredging robot.This paper mainly did the following work:The bending static models of two flexible arms are established and verified by experiments.Through mechanical analysis,the relationship between the spring’s deformation angle,spring structural parameters and material properties under the action of bending moment is established,and the bending angle of the steel wire spring and PVC composite hose under the action of the swing cylinder moment is derived.The relationship between diameter and wall thickness;an experimental device for bending characteristics was built,and the bending characteristics of two flexible manipulators were tested.The bending stiffness of the spring-type flexible arm decreases with the increase of the bending angle.The height of the spring and the guiding position of the drive wire rope have a greater influence on the bending characteristics;compared with the spring,the composite hose has better linearity when bending.Completed the construction of the flexible arm bending experiment platform.The bending characteristic experiment of the mechanical spring-type flexible arm is carried out and the bending stiffness fitting curve is drawn.It is concluded that the bending stiffness decreases with the increase of the bending angle.The height of the spring and the position of the guide ring affect its bending difficulty.Experiments on the bending characteristics of the flexible arm of the flexible tube verify the correctness of the model.The swing cylinder moment,wire diameter,and PVC wire diameter and thickness all have an effect on its bending angle,and it changes linearly in a small range.The bendability of the mechanical spring-type flexible arm is applied to the image acquisition device of the pipeline inspection robot,which realizes the bending of the camera in any direction,and the bending angle can be greater than 90°,which expands the field of vision of the pipeline inspection robot;The composite hose flexible arm is applied to the suction pipe swing device in the dredging robot,and the swing range of the suction port is expanded to ±50°.Designed the RTU-based robot motion control system for the entire robot system,completed the related hardware selection and module design,used Altium Designer to draw the circuit wiring diagram;The control interface of the drainage pipe robot is designed by Labview,which realizes the remote control of the drainage pipe robot.The pipeline inspection robot and pipeline dredging robot developed by the flexible manipulator have been successfully tested in the field.The spring-based camera can be controlled and adjusted arbitrarily on the water and underwater,which plays an important role in observing pipeline damage close to the wall.The sludge pumping system of the dredging robot based on the composite hose has significantly expanded its cleaning range and improved the quality and efficiency of dredging.